Where by Rules of Court the Registrar is authorized to make payments of money to persons entitled thereto upon their request by transmitting to them by post crossed cheques or other documents intended to enable them to obtain payment of the sums expressed therein, the posting of a letter containing a cheque or document and addressed to the person entitled thereto at the address given by him in his request shall, as respects the liability of the Registrar and of the Public Account respectively, be equivalent to the delivery of the cheque or document to that person himself.